Android S:SurfaceFlinger之SurfaceControl.java的用途

Handle to an on-screen Surface managed by the system compositor.
SurfaceControl是一个句柄，该句柄是指向由系统合成器管理的屏幕上Surface。

The SurfaceControl is a combination of a buffer source, and metadata about how to display the buffers.
SurfaceControl是缓冲区源和有关如何显示缓冲区的元数据的组合。

By constructing a {@link Surface} from this SurfaceControl you can submit buffers to be composited.
通过从此SurfaceControl构建{@link Surface}，可以提交要合成的缓冲区。

Using {@link SurfaceControl.Transaction} you can manipulate various properties of how the buffer will be displayed on-screen.
使用{@link SurfaceControl.Transaction}可以处理缓冲区在屏幕上显示方式的各种属性。

SurfaceControl’s are arranged into a scene-graph like hierarchy, and as such any SurfaceControl may have a parent.
SurfaceControl被安排成类似场景图的层次结构，因此，任何SurfaceControl都可能有父对象。

Geometric properties like transform, crop, and Z-ordering will be inherited from the parent,
几何特性（如变换、裁剪和Z顺序）将从父对象继承，
as if the child were content in the parents buffer stream.
就好像子对象是父缓存流中的内容一样。

77  /**
78   * Handle to an on-screen Surface managed by the system compositor. The SurfaceControl is
79   * a combination of a buffer source, and metadata about how to display the buffers.
80   * By constructing a {@link Surface} from this SurfaceControl you can submit buffers to be
81   * composited. Using {@link SurfaceControl.Transaction} you can manipulate various
82   * properties of how the buffer will be displayed on-screen. SurfaceControl's are
83   * arranged into a scene-graph like hierarchy, and as such any SurfaceControl may have
84   * a parent. Geometric properties like transform, crop, and Z-ordering will be inherited
85   * from the parent, as if the child were content in the parents buffer stream.
86   */
87  public final class SurfaceControl implements Parcelable {